Accuracy of delivery of cefazolin, chloramphenicol, and vancomycin by a controlled-release membrane infusion device

The effects of flow rate and drug concentration on the accuracy of in vitro delivery of cefazolin, chloramphenicol, and vancomycin by a new controlled-release membrane infusion device, MICROS, were studied. Cefazolin, chloramphenicol, and vancomycin 1 g in sterile water for injection 10 mL were injected into the drug chamber of the device and delivered through an administration set with 0.9% sodium chloride injection from a primary line. Drug delivery was studied at four flow rates (0.5, 1.0, 1.5, and 2.0 mL/min). In addition, three concentrations of each drug (25, 50, and 100 mg/mL for cefazolin and vancomycin, and 50, 100, and 200 mg/mL for chloramphenicol) were studied at a fixed flow rate of 1 mL/min. Samples were collected in triplicate every 2.5-5.0 minutes using a fraction collector over a 90-minute period for cefazolin and a 120-minute period for chloramphenicol and vancomycin. The concentration of each drug was measured by high-performance liquid chromatography. At various flow rates, the time for delivery of greater than or equal to 95% of each dose ranged from 30 to 55 minutes for cefazolin, 45 to 70 minutes for chloramphenicol, and 50 to 65 minutes for vancomycin. At various concentrations, greater than or equal to 95% of each dose was delivered in 40 to 55 minutes for cefazolin, 40 to 70 minutes for chloramphenicol, and 50 to 60 minutes for vancomycin. The desired delivery times were 30-60 minutes for cefazolin and chloramphenicol and 50-70 minutes for vancomycin. Delivery of cefazolin and vancomycin by the MICROS membrane infusion system was accurate. Some delay was encountered in the delivery of chloramphenicol.(ABSTRACT TRUNCATED AT 250 WORDS)